In recent years, network scanners are used generally, wherein image data obtained by reading from a document are stored in a predetermined memory section, and the image data as read are transmitted to one or a plurality of terminals. Japanese Unexamined Patent Application No. 2000-349952 (published on Dec. 15, 2000) discloses a network scanner wherein a hyper text (so-called thumbnail) that includes a list of reduced images of image data as read by a network scanner is transmitted to the terminal, and by making an access to the linked address where reduced images are stored, the corresponding image data are transmitted to the terminal of the requesting end.
When reading the document by the foregoing network scanner, the user generally sets various image reading conditions, such as resolution, density, etc., (hereinafter simply referred to as reading conditions). In order for the user to confirm if the image data as he/she desires are obtained, the image data as read are opened using a predetermined application software to confirm the image data on a screen or a print sheet with his/her eyes. Therefore, the user often changes the set reading conditions while observing the image data on the screen.
In the case of network scanner, in order to perform the foregoing operation of changing the reading conditions, it is necessary to transmit the image data as read to the terminal via the network, for the user to confirm the image data at the terminal. In some cases, it is also necessary to transmit the image data as read to a plurality of terminals for respective users at the terminals to determine if any change in reading conditions are necessary.
However, since a volume of the image data is generally large, the foregoing repetitive operations of checking the set reading conditions or confirming the image data would increase a load on communicating in the network, which affects other communications within the network. Furthermore, an increased communication load would also make the communication time longer, which in turn causes such problem that it takes time for the user to obtain the image data as desired.
According to the structure disclosed by the Japanese Unexamined Patent Application No. 2000-349952, it is possible to suppress the communication load to some extent by arranging such that only the thumbnail is to be transmitted. However, it is not possible for the user to confirm the detailed conditions for the read image (i.e., if the set conditions for the resolution, density, are appropriate) only based on the thumbnail. Furthermore, it is troublesome for the user at the terminal to obtain the necessary image data again after once obtaining the thumbnail. Besides, the load on communication would increase by the transmission of the thumbnail from the network scanner.